Process for producing alcohols from esters of nonaromatic carboxylic acids



Patented May 4, 1937 PATENT OFFICE PROCESS FOR PRODUCING ALCOHOLS FROM ESTERS F NONABOHATIC CARBOXYLIC ACIDS Wilbur A. Lau'er, Marshallton, DeL, assignor to E. I. du Pont de Nemours a Company, Wilmington, Del., a corporation of Delaware No Drawing.

Application August 20, 1932,

Serial No. 629,754

49 Claims.

This invention relates to the production of alcohols, and more particularly to the conversion of esters of carboxylic acids to the corresponding alcohols.

This application is a continuation in part of my copending application Serial No. 445,224, filed April 1'7, 1930. a

For many years the successful reduction of acids to the corresponding alcohols has depended upon the tedious and expensive treatment of the acid in absolute alcohol solution with metallic sodium, typified in general by the method of Bouveault and Blanc (Chemisches Centralblatt 1904, II, 184; 1905, II, 1700). The advantages accruing from the use of catalytic methods of hydrogenation are manifold and such methods have largely replaced the older chemical methods of reducing unsaturated compounds to the corresponding saturated bodies. Esters of carboxylic acids, however, represent an important class of unsaturated compounds which thus far have not yielded to the known methods of catalytic hydrogenation.

I have made an exhaustive study of the hydrogenation of esters by the prior art methods, including both the ordinary liquid phase static and vapor phase flow processes. I have worked with liquid-containing systems athydrogen pressures up to 3500 lbs. per sq. in. and temperatures up to 200 C. and have found that practically no hydrogen is absorbed by lactates, valerates, butyrates, or acetates, even when using the most active copper and nickel catalysts available. Again, when the vapor of methyl formate was passed over a copper-copper oxide catalyst together with hydrogen at ordinary pressure and a temperature of 180 C., substantial gaseous decomposition took place with. the formation of oxides of carbon, formaldehyde, and formic acid. Methanol was formed only in traces.

The above mentioned experiments, together with many other along the same general line, have finally led to the discovery of a completely successful method of hydrogenating esters. I

have found that the hydrogenation of these compounds to produce alcohols is successful only when operating with active hydrogenating catalysts under superatmospheric pressure, at moderately high temperatures, and with an ample supply of hydrogen. For most low boiling esters, such as ethyl acetate, the preferred temperature is in excess of the probable critical temperature of the ester. It follows in these cases that the process may suitably be operated as a vapor phase process.

This invention has as an object to provide a process for the conversion of esters of carboxylic acids, said acids containing more than one carbon atom. per carbon] group, to the corresponding alcohols. A specific object of the present invention resides in the conversion, by hydrogenation, 5 of estersof aliphatic carboxylic acids to the corresponding alcohols. A further object is to provide a process for obtaining the corresponding alcohols from esters of aliphatic acids which contain as substituents aromatic groups. A still further object is to provide an improved hydrogenation process for the production of the rare alcohols from the corresponding esters. It is also an object to catalytically hydrogenate esters of polybasic aliphatic acids and of hydroxy and ketonic acids to the corresponding polyhydric alcohols. Another object is to carry out the above mentioned processes by theuse of highly efflcient composite hydrogenation catalysts. Other objects will appear hereinafter.

These objects are accomplished by the following invention which, in its general aspects, comprises admixing the ester to be converted with hydrogen, andheating the ester-hydrogen mixture in the presence of and in contact with a hydrogenating catalyst comprising either a single hydrogenating metal or its oxide, or a mixture of reduced hydrogenating metals and their oxides at an elevated temperature and pressure.

In the following examples I have set forth several of the preferred embodiments of my invention, but they are presented for purposes .of

' suitable for use in catalytic gas apparatus.

' Twenty-five cc. of the mixed chromite catalyst preparedas above is loaded into an alloy steel reaction vessel capable of being heated and withstanding high pressures. The tube is fitted with a preheater, a pump for injecting liquid ester at a constant rate, a T-connection for introducing hydrogen under pressure, a suitable condenser and trap for separating liquid products, and exit control valves.

The catalyst is heated to and maintained at 370 C. The hydrogen pressure is allowed to l build up to 3200 lbs. per square inch and under these conditions a mixture of 175 cc. of liquid ethyl acetate and 300 liters of hydrogen, measured at ordinary conditions of temperature and pressure, are passed through the-reaction system per hour. With good cooling, the liquid products nearly equal in volume the ester pumped into the system. By determination of the saponiflcation value of the condensate and by distillation analysis, it is found that 75% of'the ethyl acetate has been converted into ethanol.

When the process just described is carried out at a slightly higher temperature and a lower space velocity, partial condensation of the reduction products takes place with the formation of a higher alcohol. Thus, butanol is formed from ethyl acetate in substantial yields, in addition to ethanol. For example, when ethyl acetate was passed over the catalyst at the rate of 50 cc. per hour under the conditions given in the above example, the condensate contained 26.6% of saturated oily products consisting almost entirely of butanol and higher alcohols. As the rate of ilow of the ethyl acetate is increased, the formation of higher alcohols by con-.

densation decreases.

Example 2.A copper catalyst is prepared by fusing 8 parts by weight of pure copper oxide with one part of zinc oxide and one partof magnesium oxide. The cooled mass is crushed,

screened, and'reduced at 150 C. in a stream of diluted hydrogen containing 80% carbon dioxide and 20% hydrogen. Ethyl n-butyrate is pumped over 25 cc. of catalyst at the rate of 220 cc. of liquid ester per hour, together with hydrogen at the rate of 385 liters per hour, giving a hydrogen-ester molecular ratio of about senting in all a conversion of about 50%- of the ester toalcohol.

Example 3.N-butyl acetate is hydrogenated by passing it, togetherwith hydrogen, over a catalyst prepared as described in Example 1.

At atemperature of 350, C. and a pressure of 3000 lbs. there is formed an .equimolecular mixture of liquidn-butylacetate bylvolume isrpassedj.

. over one partby volume of catalyst-perzhour with a hydrogen-ester-molecular'ratioof --1 to 1. Example 4.--'-A' copper'chromite prepared by igniting-copper to itsdecomposition temperature.v The case taking plate-in the DresenceSof-hYdtOil l during the reaction. Two hundred cc'. of*:- liquid n-butylacetate and'280-300' liters are passed over 25 of the. catalystzperghour at a temperature of 325 C. nactsof: 2 00-3200 lbs. per square inch. rne. eiilu'ent cdndensate contains about 64 of unconverfed n-butyl acetate per 100 cc. introduced, in dicatinga conversion to an equimolecular mixture ofethanol and butanol of 'about 20%.,

Example 5.-A catalyst prepared as described in Example l'is heated to 365 C. A mixture of ethyl laurate vapor and hydrogen in the molecular ratio of 1 to 16 is passed over the catalyst at a pressure of 3100 lbs. High conversions are obtained by pumping the hydrogen-ester mixture over the catalyst at the rate of about 200 cc. of liquid ester per hour per 25 cc. oi catalyst. Upon chilling the condensate as thus obtained solid lauryl alcohol described inExample 1 at the. rate of 285 cc. 'cr

liquid ester per hour, together with 420 liters of hydrogen per hour, giving an-ester-alcohol molecular ratio of about 10. .The pressure was 3000 lbs. and the temperature was maintained at 350 C. The difference in saponiflcation value of the ester before and after treatment indicated a conversion of 92%. From 105 cc. of liquid ethyl phenylacetate passed over the catalyst there was obtained by vacuum distillation 90 cc. of phenylethyl alcohol, together with a little styrene.

Example 7.A sample of 93% n-butyl n-butyrate was subjected to hydrogenation over the catalyst of Example 1. The rate of flow was 700 cc. of ester per 100 cc. of catalyst per hour. The system was heated to 346 C. and maintained at a pressure of 2600-3200 lbs. The hydrogenester molecular ratio was 13.8. From 710 cc. 'of the butyrate so treated there was obtained by distillation 580 cc. of pure n-butanol boiling at 117 C., representing a conversion ofthe. ester to butanol of approximately 73% of the theoretical. r i

Example 8.-Twenty-flve cc. of a catalyst prepared as in Example 1 was loaded into a converter and heated to a temperature of 380 C. in a stream of hydrogen. The pressure was maintained'at 3000 lbs. per square inch while a mixture of hydrogen and ethyl acetate vapor was pumped overthe catalyst for 2.5 hours in order q to obtain steady'operating conditions. Without interrupting the flow or changing the conditions of temperature or pressure, the pump was switched from ethyl acetate to a supply of ethyl adipate (the diethyl ester of adipic acid). Seven hundred and fifty ave cc. of this ester was pumped through the reaction system in three hours, during which time the vvoiurneof hydrogen, measured at ordinary conditions of temthere was obtisined736 cc. 0f liquiti'products. A

comparison of the saponiiicationyvalues before and after treatment showed'that 'theester con- :tenthad dropped about 53%. By careful vac-. uum distillation, there was obtained 210- grams of W A r I fg-hexamethylene 'glycol'boiling at 143 144 C. at be reduced in a stream of hydrogen prior-Wi ts or it may be employed 'directly,jreductionqin.;-thisl a pressure of! mm. "This value corresponds to -l 'The' hydrogenation of ethyl adipate atslightly -highcr temperatures and lower rates oi flow than those specified in the above example rein theformationof secondary hydrogenation products consisting of one or more monohydric alcohols.

' 1 Example 9.-'- Fifteen hundred grams. of copper nitrate dissolved in 4 liters of water was mixed with a solution containing 1000 grams of am 'mohium .chromate inan equal volume of water.

Ammonium hydroxide was added to neutralize the acidity. developed during precipitation-of the perature and pressure, passed'throu h'f c n. a lystwas 560 liters. 'By'cooling thejexitlvaporsr .4a% of the glycol theoreticall'y'obtainable from 5 volume of. diethyl adipate' treated.

copper ammonium chromate. The precipitate was washed by decantation, filtered, and dried, after which it was ignited at a temperature to 400 C. The resulting copper chromite powder was employed for the hydrogenation of esters without further treatment. One hundred fifty grams of ethyl azelate and grams of copper chromite, prepared as described, were placed in a shaking autoclave. Hydrogen was introduced until the pressure reached 3000 pounds per square inch. The mixture was heated to 270 C. and agitated for four hours, after which the absorption of hydrogen had ceased. on recovery and separation of the products, it was found that the yield of nonamethylene glycol was approximately 50%.

In another experiment. carried out under approximately the sann conditions except that the temperature was raised to 325 ethyl sebacate' was hydrogenated in good yields to ethanol and decamethylene glycol. Good results were also obtained by the use of butanol as a diluent for the esters in this process.

Example'10.-Copper chromite prepared as described in Example 9 was extracted with 10% acetic acid, washed and dried. One hundred fifty grams of ethyl oleate and grams of the extracted copper chromite were agitated in a shaking autoclave at 250 C. and under a hydrogen pressure of 4900 lbs. After two hours treatment in this manner it was found that the ester had been converted in 83% yields to ethyl alcohol and a mixture of oleyl and stearyl alcohols.

Example 11.-The applicability of the process to the production of dihydrlc alcohols from the esters of certain hydroxy acids is aptly illustrated by an experimental run carried out with ethyl ricinoleate. This ester was passed with hydrogen over cc. of the catalyst described in I Example 1 at the rate of about 200 cc. per hour. The average pressure was 2570 lbs. per square inch, the average temperature 370 C., and the rate of hydrogen flow 7.7 cu. ft. per hour. The

; saponiflcation value of the condensed product indicated a conversion to alcohols amounting to about 65%. In order to remove the remaining olefinic unsaturation, the products were subjected to a further hydrogenation with a nickel catalyst in the liquid phase at 100 C. After distilling off the ethyl alcohol there remained a white solid material consisting of about equal parts of octadecanediol and stearyl alcohol together with a lesser amount of the esters of these alcohols.

Example 12.The diethyl ester of succinic acid was vaporized and passed over the catalyst described in Example 1 together with hydrogen at the rate of 8 volumes of the liquid ester per unit volume of catalyst per hour at a temperature of 367 C. and a pressure of 2500 lbs. per square inch. The hydrogen-ester molecular ratio was about 10. Analysis of the condensed products showed that the ester had been hy- 'drogenated to the extent of about 75%, the principal products being tetramethylene glycol and tetrahydrofurfurane.

Example 13.-Twenty-six g. of barium nitrate and 218 g. of cupric nitrate are dissolved in is then extracted twice with 10% acetic acid, washed and dried.

In an alloy steel tube having a capacity of about 400 cc. is placed 252 g. (1.25 moles) of diethyl adipate (b. p. 144-145/29 mm.) and 20 g. of copper chromite catalyst prepared as described above. The tube is closed, made, gastight, and secured in a suitable agitating device. Connection'is made with the hydrogen supply and hydrogen is introduced until a pressure of about 2000 lbs. per square inch is reached. Agitation is started and the reaction system is heated as rapidly as possible to 255C. Additional hydrogen is now admitted to a total pressure of 3000 lbs. per square inch. The temperature is maintained at 255 C. while hydrogen is introduced periodically to maintain the pressure between 2500 and 3000 lbs. After 2-2.5 hours, .the

rate of absorption of hydrogen becomes quite slow. At this point the temperature is decreased to 240 C. and the hydrogenation is continued until hydrogen absorption is complete. The agitation is stopped and the tube closed off, cooled,

and the pressure released. The contents are transferred to a 600 cc. beaker with the aid of four 25cc. portions of 95% alcohol. The catalyst is removed by filtering with suction and is washed on the filter with four more 25 cc. portions of alcohol. Fifty cc. of 40% sodium hydroxide is added and the alcoholic solution is boiled for 2 hours under a reflux condenser. The solvent is distilled 011. up to a temperature of 95. The residue is then transferred to an apparatus for the continuous extraction of liquids and is exhaustively extracted with ether. The ether is distilled and after the removal of water and alcohol the glycol is distilled under vacuum in a 250 cc. Claisen flask. The yield is 125 to 132 g., or 85 to 90% of the theoretical amount. Hexamethylene glycol boils at 143-144 (bath at 160) under 4 mm. pressure and melts at 41-42.

Although certain definite conditions of operation, such as temperature, pressure, and rate of flow of the material to be treated over the catalyst, have been indicated in the above examples, it will be apparent that these factors may be varied within wide limits within the scope of my invention. The catalytic reduction of carboxylic esters to alcohols requires the use of temperatures and pressures appreciably higher than customarily used for carrying-out a given reaction. In operating in the vapor phase it is preferred to use temperatures within the range of 300 C. to 400 C. The success of the process also depends on the use of an elevated pressure in excess of 25 atmospheres, while the preferred pressure is about 50-250 atmospheres per square inch. The maximum pressure which can be used is limited only by the strength of the reaction apparatus. It is to be understood that my invention is not limited to the use of these specific pressures, since they may be varied depending upon the ester treated and the amount of conversion desired. As the pressure is decreased, it will be evident that the conversion to alcohol will decrease in accordance with the well known law of mass action.

In the selection of suitable conditions of temperature and pressure, it is well to remember that the catalytic hydrogenation of esters is a re- 1,746,783 wherein a double ammonium chromate of a hydrogenating metal is heated at about a 600 C. to form a chromite catalyst. As indicated in the examples success has attended the use of mixtures of the chromites of two or more hydrogenating metals. 'The multiple chromite catalyst compositions described in the examples and disclosed in my copending application Serial No. 470,238, filed July 23, 1930, are eminently suited to use in the present invention. The multiple chromite catalyst compositions described in the said copending application may be prepared by precipitation of a mixture of chromates from solution by adding an alkali metal chromite to an aqueous solution of a mixture of hydrogenating metal salts, followed by ignition or by high temperature treatment with hydrogen. I prefer to use a chromite composition consisting substantially of zinc chromite but containing lesser quantities oi. the chromates or chromites of copper and cadmium. The activity of chromite catalysts may be further enhanced by subjecting the ignited chromites to an acid extraction process which serves to remove from the composition a portion of the hydrogenating metallic oxide which is not combined with the promoter oxide.

The advantages attending the use of difficultly reducible oxides or reducible oxides in a difflcultly reducible form are several and substantial. These catalysts possess a high activity and are sturdy in character. They are relatively immune to degenerative processes such as sintering or poisoning, being thus distinguished from metal catalysts which deteriorate rapidly when subjected to excessive heating. Unlike certain metal catalysts, they possess a small tendency to carry the hydrogenation beyond the alcohol stage, for example to the production of the corresponding hydrocarbon.

I wish to make mention of the utility of catalysts containing copper oxide promoted by chromium oxide either in physical mixture or in chemical combination as copper chromate or copper chromite. This catalyst is particularly use- In! for liquid phase ester hydrogenation reactions.

The catalysts described above, in addition to the modified copper-chromium catalysts last mentioned, may be modified or promoted by the addition of oxides or carbonates of alkali metals or oi alkaline earth metals, or of basic compounds of alkali metals or of alkaline earth metals, that is, compounds of these alkali-forming metals with acids which are weaker than the metal hydroxide. Other suitable promoters are compounds containing an alkali or alkaline earth metal combined with the acid radical of an oxygen-containing acid, e. g., barium chromate. These compounds will all be classified under the term basic compounds of alkali- One tendency of the basic tion to hydrocarbon of the formed alcohol.

It will be apparent from the above examples that the method of the present invention is applicable in general to the hydrogenation of esters of non-aromatic, i. e., aliphatic and alicyclic carbexylic acids having more than one carbon atom per carboxyl group,'but it may be used with particular advantage for the hydrogenation of the esters of non-aromatic monobasic acids to the corresponding monohydric alcohols. Typical acids of this class are acetic, propionic, butyric, caprylic, lauric, capric, myristic, palmitic, linoleic, linolenic, oleic, ricinoleic, stearic, hexahydrobenzoic and hexahydrotoluic acids. The process is also valuable for the hydrogenation of esters of non-aromatic dibasic and other polybasic acids to the corresponding glycols and other polyhydric alcohols. Such acids are: hexahydrophthalic, azelaic, sebacic, succinic, suberic, pimelic, nonanedicarboxylic, decamethylenedicarboxylic, brassylic, dodecamethylene dicarboxylic, hexadecamethylenedicarboxylic, and adipic. The process is also applicable to the hydrogenation of esters of aralkyl acids, which are a species under the class aliphatic acids. Thus, the process is applicable to the esters of such acids as, phenylacetic, phenylpropionic, cinnamic, etc. The hydrogenation of ethyl phenylacetate is described in Example 6 above. The process is also applied effectively to the hydrogenation of esters of hydroxy, aldehydic, and ketonic acids, e. 3.. lactic, ricinoleic, tartaric, and pyruvic acids, yielding thereby various useful glycols. The process is also applicable to the treatment of mixtures of esters, for example, to the ethyl esters of the mixed acids obtained by the saponification of a fat such as coconut oil, the mixed acids being esterified with ethyl alcohol without separation into the individual components of the mixture. Included within the scope of the invention is the hydrogenation of esters of hydroaromatic acids, e. g., the naphthenic acids, which are included under the term esters of non-aromatic acids. By the term esters of non-aromatic carboxylic acids", as used herein and in the claims, I mean to include only esters of acids of the various classes enumerated above. Among the esters to which the present process is applied are the esters ofglycerol, glycol and other p lyhydric alcohols and mono and polyesters of the acids 'named above.

The process is applicable to the type of esters commonly known as waxes, either synthetic or naturally occurring, which on hydrolysis yield high molecular weight aliphatic carboxylic acids and high molecular weight alcohols, e. g., beeswax, spermaceti, carnauba wax and the like.

, Where the ester is an ester of a polyhydric alcohol it may be a mono ester or a polyester. Where the ester is an ester of a polycarboxylic acid, it may likewise be a mono ester or a di ester.

The process of my invention also finds application in the conversion of an acid to the corresponding alcohol. I prefer to first form the ethyl ester of the acid in question and subject this compound to hydrogenation in the presence of.composite hydrogenating catalysts. In this manner the ethyl alcohol originally employed may be recovered for reacting with a fresh portion of the acid. Methyl alcohol is not \as valuable for this purpose, since it is subject to gaseous decomposition during the hydrogenation process. Alcohols such as butanol and propanol may be used successfully when combined as esters with the acids to be reduced.

' Aliphatic acids and their derivatives occur in abundance in nature, while the corresponding alcohols are found rarely, if at all. By application of the process of my invention, it is now possible to prepare alcohols from the corresponding acids by first converting these acids to their alkyl esters and hydrogenating the esters under pressure. The usual chemical reducing agents are expensive and have rendered the cost of producing rare alcohols impractical, but by the use of the present invention this obstacle has been removed, thereby widening the use these comparatively rare materials in the arts.

The above detailed description contains no specific mention of thehydrogenation oi esters of aromatic acids. However, it aromatic acid esters are subjected to hydrogenation under the conditions' relating to temperature, pressure, catalysts, etc., described above 'withrespect to aliphatic and hydroaromatic acid esters, hydrogenation willtake the esterhowever being preferentially reduced to a hydrocarbon instead of an alcohol. benzoate yields toluene and ethyl alcohol while benzyl benzoate, under the same conditions yields of non-aromatic acids.

toluene. The broadest scope. of the invention therefore is intended to include the hydrogenation of aromatic acid esters although the preferred form relates to the hydrogenation of esters The above description and examples are to be taken as illustrative only and not as limiting the scope of the invention. Any modification or variation therefrom which conforms to the spirit of the invention is intended to be included within the scope of the claims.

I claim:

1. The process of producing an alcohol from an ester of a non-aromatic carboxylic acid, said alcohol corresponding inrnumber of carbon atoms to said acid, which comprises treating with hydrogen an ester of a non-aromatic carboxylic acid, the number of carbon atoms in said acid being greater than the number of carboxyl groups, at a drogen an of' a non-aromatic carboxylic acid, the. number-of carbon atoms in said'acid to said acid, which comprises treating with hy- 1 temperature in excess or 200 C. and under a superatmospheric pressure in the presence oi. a

hydrogenation catalyst.'

2. The process of producing an alcohol from an ester of a non-aromatic carboxylic acid, said alcohol corresponding in number of carbon atoms to said acid, which comprises treating with hybeing greater than the number of carboxyl groups, at a temperature lnexcess of 200 C. and under a superatmospheric pressure in the presence or a hydrogenation catalyst characterised by. being suitable for e synth'esis ofmethanol from water gas.

3. 'Ihe'processfioi producing an alcoholirom an ester of a non-aromatic carboxylic acid, said alcohol corresponding" in number. of carbon atoms drogen an ester of a non-aromatic carboxylic acid, the numberot carbon atoms in said 'acid being greater than the number of 'carboxyl groups,

at a temperature in excess oi. 200 C. and under 7 a superatmospheric pressure in the presence of a 3 component a hydrogenating metal.

hydrogenation catalystcomprising as an essential 4-. The process otproducing an alcohol from an 5. The process of producing an alcohol from V an ester oi. a non-aromatic carboxyiic acid, said alcohol. corresponding in number of carbon atoms -to said acid, which comprises treating with hydrogen an'e'ste r of. a non-aromatic carboxylic Thus the hydrogenation .of ethyl acid. the number of carbon atoms in said acid being greater than the number of carboxyl groups, at a temperature in excess of 200 C. and under a superatmospheric pressure in the presence of a copper-containing hydrogenation catalyst.

6. The process oi producing an alcohol from an ester of a non-aromatic carboxylicacid, said alcohol corresponding in number oi carbon atoms to said acid, which comprises treating with hydrogen an ester of a non-aromatic carboxylic acid, the number of carbon atoms in said acid being greater than the number of carboxyl groups, at a temperature in excess of 200 C. and under a superatmospheric pressure in the presence of a zinc-containing hydrogenation catalyst.

7. Theprocess of producing an alcohol from an ester of a non-aromatic carbonlic acid, said alcohol corresponding in number 01' carbon atoms to said acid, which comprises treating with hydrogen an ester of a non-aromatic carboxylic acid, the number of carbon atoms in said acid being greater than the number of carboxyl groups, at a temperature in excess 0! 200 C. and under a superatmospheric pressure in the presence of a hydrogenation catalyst comprising as an essential component copper in combination with a hydrogenating metal oxide, said oxide being one which when exposed in a state of .purity to the action of hydrogen at atmospheric pressure and at a temperature of 400 C. to 450' C. or a prolonged period of time, remains substantially in the oxide form.

8. The process of producing an alcohol from an ester of a non-aromatic carboxyllc acid, said alcohol corresponding in number of carbon atoms to said acid, which comprises treating with hydrogen an ester of a non-aromatic carboxylic acid, the number .01 carbon atoms in said acid being greater than the number of carboxyl groups, at a temperature in excess of 200 C. and under a superatmospheric pressure in the presence 01 a hydrogenation catalyst comprising as an essential component a hydrogenating metal intimately associated with a metal oxide more acidic than the oxide of the said hydrogenating metal.

9. The process of producing an alcohol from an ester of a non-aromatic carboxylic acid, said alcohol corresponding in number oi atoms to said acid, which comprises-treating with hydrogen an ester of a non-aromatic carboxylic acid, the number or carbon atoms in said acid being greater than the number crcsrboxyl groups, at a temperature in excess of 200: C. and-under a superatmospheric pressure in the presence of a hydrogenation catalyst comprising as an essential 5 component a hydrogenating metal oxide intimately associated with a metal oxide more acidic than the said hydrogenating metal oxide.

4 10.; The process of producing an alcohol from ester of a non-aromatic carboxylic acid, said alcohol corresponding in number of carbon atoms to said acid, which comprisu treating with hydrocomponent a hydrogenating metal oxide intimate- -ly associated with chromium oxide.

- 11. The process 01' producing analcohol from an ester of a non-aromatic carboxylic acid, said alcohol corresponding in number of carbon atoms to said acid, which comprises treating with hydrogen an .ester of a non-aromatic carboxylic a superatmospheric pressureln the presence of a hydrogenation catalyst comprising as an essentialcomponent copper oxide intimately associated with chromium oxide.

12. The process of producing an alcohol from an ester of a non-aromatic carboxylic acid, said alcohol corresponding in number of carbon atoms to said acid, which comprises treating with hydrogen an ester of a non-aromatic carboxylic acid, the number of carbon atoms in said acid being greater than the number of carboxyl groups, at a temperature in, excess ot 200 C. and under a superatmo'spheric pressure in the presence of a hydrogenation catalyst comprising as an essential component copper chromite.

13. The process of producing analcohol from an ester of a non-aromatic carboxylic acid, said alcohol corresponding in number of carbon atoms to said acid, which comprises-treating'with hydrogen an ester of a non-aromatic carboxylic acid, the number of carbon atoms in said acid being greater than the number of carboxyl groups, at a temperature in excess of 200 C. and under a. superatmospheric pressure in the presence of a hydrogenation catalyst comprising as an essential component zinc chromite.

14. The process of producing an alcohol from an ester of an aliphatic mono-carboxylic acid, said alcohol corresponding in number of carbon atoms to said acid, which comprises treating with hydrogen an ester of an aliphatic monocarboxylic acid, said acid containing at least two carbon atoms, at a temperature in excess of 200 C. and under a superatmospheric pressure in the presence of a hydrogenation catalyst.

15. The process of producing an alcohol from an ester of an aliphatic mono-carboxylic acid, said alcohol corresponding in number of carbon atoms to said acid, which comprises treating with hydrogen an ester of an aliphatic mono-carboxylic acid, said acid containing at least two carbon atoms, at .a temperature of between 240 C. and 400 C. and under a pressure in excess of twenty-five atmospheres in the presence of a hydrogenation catalyst.

16. The process of producing an alcohol from an ester of a saturated aliphatic mono-carboxylic acid, said alcohol corresponding in number of carbon atoms to said acid, which comprises treating with hydrogen an ester of a saturated aliphatic mono-carboxylic acid, said acid containing at least two carbon atoms, at a temperature of between 240 C. and 400 C. and under a pressure in excess of 25 atmospheres in the presence of a hydrogenation catalyst.

17. The process of producing an alcohol from an alkyl ester of an aliphatic mono-carboxylic acid, said alcohol corresponding in number of car'- bon atoms to said acid, which comprises treating with hydrogen an alkyl ester of an aliphatic mono-carboxylic acid, said acid containing at least two carbon atoms, at a temperature in excess of 200 C. and under a superatmospheric pressure in' the presence of a hydrogenation catalyst.

18. The process of producing an alcohol from tween 240 C. and 400 C. and under a pressure in excess of twenty-five atmospheres in the presence of a hydrogenation catalyst.

19. The process of producing an alcohol from an ester of an aliphatic dicarboxylic acid, said alcohol corresponding in number of carbon atoms to said acid, which comprises treating with hydrogen an ester of an aliphatic dicarboxylic acid, said acid containing at least three carbon atoms, at a temperature in excess of 200 C. and under a superatmospheric pressure in the presence of a hydrogenation catalyst.

20. The process of producing an alcohol from an ester of adipic acid, said alcohol corresponding in number of carbon atoms to said adipic acid, which comprises treating with hydrogen an ester of adipic acid at a temperature in excess of 200 C.

and under'a superatmospheric pressure in the presence of a hydrogenation catalyst.

21. The process of producing an alcohol from an ester of an aliphatic carboxylic acid having a phenyl substituent, said alcohol corresponding in number of carbon atoms to said acid, which phenyl acetic acid, which comprises treating with hydrogen an ester of phenyl acetic acid at a temperature in excess of 200 C. and under a superatmospheric pressure in the presence of a hydrogenation catalyst.

23. The process of producing an alcohol from an ester of a non-aromatic carboxylic acid, said alcohol corresponding in number of carbon atoms to said acid, which comprises treating with hydrogen an ester of a non-aromatic carboxylic acid, the number of carbon atoms in said acid being greater than the number of carboxyl groups, at a temperature in excess of 200 C. but below 400 C. and under a superatmospheric pressure in the presence of a hydrogenation catalyst.

24. The process of producing an alcohol from an ester of a non-aromatic carboxylic acid, said alcohol corresponding in number of carbon atoms to said acid, which comprises treating with hydrogen an ester of a non-aromatic carboxylic acid, the number of carbon atoms in said acid being greater than the number of carboxyl groups, at a temperature of between 240 C. and 400 C. and under a superatmospheric pressure in the presence of a hydrogenation catalyst. 25. The process of producing an alcohol from an ester of a non-aromatic carboxylic acid, said alcohol corresponding in number of carbon atoms to said acid, which comprises treating with hydrogen an ester of a. non-aromatic carboxylic acid, the number of carbon atoms in said acid being greater than the number of carboxyl groups, at a temperature of between 240 C. and 400 C. and under a pressure in excess of twenty-five atmospheres in the presence of a hydrogenation catalyst characterized by being suitable for the synthesis of methanol from water gas.

2.6. The process of producing an alcohol from an ester of a non-aromatic carboxylic acid, said alcohol corresponding in number of carbon atoms to said acid, which comprises treating with hydrogen an ester of a, non-aromatic carboxylic acid, the'number of carbon atoms in said acid being greater than the number of carboxyl groups,

drogen an ester of a non-aromatic carboxylic acid,

at a temperature of between 240 C. and 400 C. and under a pressure in excess of twenty-five atmospheres in the presence or a hydrogenation catalyst comprising as an essential component a hydrogenating metal.

27. The process of producing an alcohol from an ester of a non-aromatic carboxylic acid, said alcohol corresponding innumber of carbon atoms to .said acid, which comprises treating with hydrogen an ester of a non-aromatic carboxylic acid, the number of carbon atoms in said acid being greater than the number of carboxyl groups, at a temperature of between 240 C. and 400 C. and under a pressure in excess 01 twenty-five atmospheres in the presence of a hydrogenation catalyst comprising as an essential component a hydrogenating metal oxide.

28. The process of producing an alcohol from an ester of a non-aromatic carboxylic acid, said alcohol corresponding in number of carbon atoms to said acid, which comprises treating with hydrogen an-ester of a non-aromatic carboxylic acid, the number of carbon atoms in said acid being greater than the number of carboxyl groups, at a temperature of between 240 C. and 400- C. in the presence of a copperf-containing-hydrogenation catalyst. I

29. The process oi'producin'gan alcohol from an ester of a non-aromatic carboxylicacid, said alcohol corresponding in number of carbon atoms to said acid, which comprises treating'wlth hythe number of carbon atoms in said acid being greater than the number of carboxyl groups, at a a temperature of between 240 C. and 400C. and

under a pressure in excess of twenty-five atmospheres in the presence oi a hydrogenation catalyst comprising as an essential component copper in combination with a hydrogenating metal 'ox- 'ide, said oxide being one which when exposed in a state or purity to the action of hydrogen at'atmospherlc pressure and at a temperature of 400 C. to 450 C. for aprolonged period of time re mains substantially in the oxide form.

30. Theprocess oi. producingan alcohol an ester oia non-aromatic carboxylicacid, said alcohol corresponding in number 01' carbon atoms to said-acid, which comprises treating with 'hy-I drogenan ester of a non-aromatic carboxylic acid, the number'of carbon atoms in said acid being greaterthan the number 01' carboxylgroups, at a temperature of between 240 C. and 400 C. and

under a pressure in excess of twenty-five atmospheres in. the presence oi a hydrogenation catalyst.c0mprising as an essential component a hyto said acid, which comprises treating with hy-i',

' drogen an ester, of a non-aromaticfcarboxylic j-acid, thelnumber or carbon atoms in said acid "being greater than the. number oi! carboxyl groups, at a-temperature between-240 C. and

400 C. and under a pressure in excess of twentyfiveatmospheres in the presenceoi a hydrogenasaid hydrogenating metal oxide.

- 32. The process oiproducing an alcohol from an ester of a non-aromatic carboxylicacld, said alcohol corresponding in number of carbon atoms nent zincchromite;

aso c d I eessaci"twenty-iive-atmespheresin thepresence .essentialcomponentcopperchromitep ponent a hydrogenating metal oxide intimately associated with chromium oxide.

33. The process of producing an alcohol from an ester of a non-aromatic carboxylic acid, said alcohol corresponding in number 01' carbon atoms to said acid, which comprises treating with hydrogen an ester of a non-aromatic carboxyiic acid, the number-oi carbon atoms in said acid being greater than the number of carboxyl groups, at a temperature of between 240 C. and 400." C. and under a pressure in excess of twentyflve atmospheres in the presence of a hydrogenation catalyst comprisingas an essential component copper oxide intimately associated with atoms to said acid, which comprises a with hydrogen an ester of a non-aromatic carboxylic acid, the number of carbon atoms in said .a'cidbeing greater'than the number of ;carboxyl. groups, at a temperature oizbetweenfio" C. and

400 C. and undera pressure in ot'twenty-i ilve atmospheres in thepresence' oi a'hydrogen essential V ation catalyst comprisingas an ponent copper chromite.

35. .fi l'he process of producing 1mm 7 an 'ester oi anon-aromatic carboxylic acid, said alcohol correspon ns in" number or carbon atoms to said acid," which comprises treating with hydrogen anester of a non-aromatic carboxylicaoid, the number 01' carbon atoms inand acid greatenthan the'n'umber of carbon] groups, at atemperature or between 240 C. "and 400 c. and vunder a pressure'in excess of twentyfive atmospheres in the "presence of a hydrogenaas an compotionf catalyst comprising 35. The ot-producing'an from an ester-oi a non-aromatic carbo'xylic acid, said being greater-than the number of carboxyl groups, at a temperature in excess 01200" C.

. and under apressure or atleast fifty atmospheres in the presence of a hydrogenationca'talyst, Y

37. The process of an alcohol from an oi an aiiphatic mon'o carbonlic vacid, sai alcohol corresponding'in number-.oicarbon of a hydrogenationfleatalystfcomprising an ester'oi'a saturated mono-carboxylichoid,

said alcoholcorrespondinginfnumber of carbon Y l a t W r o oms.- atate perature oi tween 240 C. and 400 C. and under a pressure in excess of twenty-five atmospheres in contact with a hydrogenation catalyst comprising as an essential component copper chromite.

39. The process of producing an alcohol from an alkyl ester of an aliphatic mono-carboxylic acid, said alcohol corresponding in number of carbon atoms to said acid, which comprises treating with hydrogen an alkyl ester of an aliphatic mono-carboxylic acid, said acid containing at least two carbon atoms, at a temperature of between 240 C. and 400 C. and under a pressure in excess of twenty-five atmospheres in contact with a hydrogenation catalyst comprising as an essential component copper chromite.

40. The process of producing an alcohol from an ester of an aliphatic mono-carboxylic acid, said alcohol corresponding in number of carbon atoms to said acid, which comprises treating with hydrogen an ester of an aliphatic monocarboxylic acid, said acid containing at least two carbon atoms at a temperature of between 240 C. and 400 C. and under a pressure of at least fifty atmospheres in the presence of a hydrogenation catalyst comprising as an essential component a hydrogenating metal.

41. The process of producing an alcohol from an ester of a non-aromatic carboxylic acid, said alcohol corresponding in number of carbon atoms to said acid, which comprises treating with hydrogen an ester of a non-aromatic carboxylic acid, the number of carbon atoms in said acid being greater than the number of carboxyl groups, at a temperature in excess of 200 C. and under a superatmospheric pressure in the presence ofa hydrogenation catalyst comprising as an essential component a member of the ferrous metal group of the Periodic Table.

42. The process of producing an alcohol from an ester of a non-aromatic carboxylic acid, said alcohol corresponding in number of carbon atoms to said acid, which comprises passing a mixture of hydrogen and an ester of a non-aromatic carboxylic acid, the number of carbon atoms in said acid being greater than the number of carboxyl groups, at a temperature between 240 C. and 400 C. and under a superatmospheric pressure in contact with a hydrogenation catalyst.

43. The process of producing an alcohol from an ester of a non-aromatic carboxylic acid, said alcohol corresponding in number of carbon atoms to said acid, which comprises passing a mixture of hydrogen and the vapor of an ester of a nonaromatic carboxylic acid, the number of carbon atoms in said acid being greater than the number of carboxyl groups, at a temperature between 300 C. and 400 C. and under a pressure in excess of twenty-five atmospheres in contact with a hydrogenation catalyst comprising as an essential component a hydrogenating metal.

44. The process of producing an alcohol from an ester of a non-aromatic carboxylic acid, said alcohol corresponding in number of carbon atoms to said acid, which comprises passing a mixture of hydrogen and the vapor of an ester of a nonaromatic carboxylic acid, the number of carbon atoms in said acid being greater than the number of carboxyl groups, at a temperature between 300 C. and 400 C. and under a pressure in excess of twenty-five atmospheres in contact with a hydrogenation catalyst comprising as an essential component a hydrogenating metal oxide.

45. The process of producing an alcohol from an ester of a non-aromatic carboxylic acid, said alcohol corresponding in number of carbon atoms to said acid, which comprises passing a mixture of hydrogen and the vapor of an ester of a nonaromatic carboxylic acid, the number of carbon atoms in said acid being greater than the number of carboxyl groups, at a temperature between 300 C. and 400 C. and under a pressure in excess of twenty-five atmospheres in contact with a copper-containing hydrogenation catalyst.

46. The process of producing an alcohol from an ester 01 a non-aromatic carboxylic acid, said alcohol corresponding in number of carbon atoms to said acid, which comprises passing a mixture of hydrogen and the vapor of an ester of a nonaromatic carboxylic acid, the number of carbon atoms in said acid being greater than the number of carboxyl groups, at a temperature between 300 C. and 400 C. and under a pressure in excess of twenty-five atmospheres in contact with a zinccontaining hydrogenation catalyst.

47.- The process of producing an alcohol from an ester of a non-aromatic carboxylic acid, said alcohol corresponding in number of carbon atoms to said acid, which comprises passing a mixture of hydrogen and the vapor of an ester of a nonaromatic carboxylic acid, the number of carbon atoms in said acid being greater than the number of carboxyl groups, at a temperature between 300 C. and 400 C. and under a pressure in excess of twenty-five atmospheres in contact with a hydrogenation catalyst comprising as an essential component a. hydrogenating metal oxide intimately associated with a metal oxide more acidic hydrogenation catalyst comprising as an essential component a hydrogenating metal oxide intimately associated with chromium oxide.

49. The process of producing an alcohol from an ester of a non-aromatic carboxylic acid, said alcohol corresponding in number of carbon atoms to-said acid, which comprises passing a mixture of hydrogen and the vapor of an ester of a nonaromatic carboxylic acid, the number of carbon atoms in said acid being greater than the number of carboxyl groups, at a temperature between 300 C. and 400 C. and under a pressure in excess of twenty-five atmospheres in contact with a hydrogenation catalyst comprising as an essential component zinc-chromite.

WILBUR A. LAZIER.

CERTIFICATE OF CORRECTION.

Patent no. 2,079,414. May 4, 1937;

WILBUR A. 'LAZIER.

It is hereby certified that error appears in the printed specification of the above numbered patent requiring correction as follows: Page 2, first column, line 63, for the word "plate" read place; page 5, second column, line 53, for "about" read above; and that the said Letters Patent should be read with these corrections therein that the same may conform to the record of the case in the Patent Office.

Signed and sealed this 27th day of July. A. D. 1937.

Henry Van Arsdale (Seal) Acting Commissioner of Patents. 

